There is no protocol in place to let R1 know that R2 will do the
forwarding, so R1 should forward.
Same rule reversed applies to R2. So I would be surprised to learn that
only one forwards...

gladston@xxxxxxxxxx wrote:

Say net A is connected to router 1 and router 2 via ethernet. Both routers are connected to router 3 via serial; a DHCP server is connected to ethernet of R3. Router 1 and 2 has the command 'ip helper-address' pointing to the DHCP server.
Will both routers, R1 and R2, forward the DHCP request coming from a station on net A to the DHCP server? Or one of them will have this role?

From my undertanding, there is no similar thing as an "ASSERT" message between router R1 and R2 so just one forward the DHCP request to the server.
Any Thoughts?